[CIFS] Don't allow a backslash in a path component

Unless Posix paths have been negotiated, the backslash, "\", is not a valid
character in a path component.

Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Steve French  <sfrench@us.ibm.com>

diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 3830dfeb31cf219e57003d8e71ab52b0df4620da..82315edc77d7daaaaaca6865ca44e4946807190c 100644 (file)
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -436,6 +436,20 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, struct name
        cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
        pTcon = cifs_sb->tcon;
 
+       /*
+        * Don't allow the separator character in a path component.
+        * The VFS will not allow "/", but "\" is allowed by posix.
+        */
+       if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
+               int i;
+               for (i = 0; i < direntry->d_name.len; i++)
+                       if (direntry->d_name.name[i] == '\\') {
+                               cFYI(1, ("Invalid file name"));
+                               FreeXid(xid);
+                               return ERR_PTR(-EINVAL);
+                       }
+       }
+
        /* can not grab the rename sem here since it would
        deadlock in the cases (beginning of sys_rename itself)
        in which we already have the sb rename sem */